SOROMOU et al Journal of Drug Delivery & Therapeutics. 2021; 11(5):16-22 ISSN: 2250-1177 [16] CODEN (USA): JDDTAO Available online on 15.09.2021 at http://jddtonline.info Journal of Drug Delivery and Therapeutics Open Access to Pharmaceutical and Medical Research Copyright © 2021 The Author(s): This is an open-access article distributed under the terms of the CC BY-NC 4.0 which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited Open Access Full Text Article Research Article Hormonal sex reversal technique of Oreochromis niloticus larvae in a tank in the Urban Commune of Kankan, Republic of Guinea Lanan Wassy SOROMOU, Berthin THEA, Yamoussa BANGOURA, Aboubacar Mabinty CAMARA, Samba MAGASSOUBA, Odia Mamady KABA, Youssouf SIDIME Higher Institute of Sciences and Veterenary Medicine of Dalaba, BP 09, Guinea Article Info: _________________________________________ Article History: Received 06 July 2021 Reviewed 03 August 2021 Accepted 10 August 2021 Published 15 Sep 2021 _________________________________________ Cite this article as: Soromou LW, Thea B, Bangoura Y, Camara AM, Magassouba S, Kaba OM, Sidime Y, Hormonal sex reversal technique of Oreochromis niloticus larvae in a tank in the Urban Commune of Kankan, Republic of Guinea, Journal of Drug Delivery and Therapeutics. 2021; 11(5):16-22 DOI: http://dx.doi.org/10.22270/jddt.v11i5.4977 ______________________________________________ *Address for Correspondence: Dr Lanan Wassy Soromou, Higher Institute of Sciences and Veterenary Medicine of Dalaba, BP 09, Guinea Abstract ______________________________________________________________________________________________________ Hormonal sex - reversal is widely recognized as having significant advantage over both manual sexing and hybridization. The present study carried out in the aquaculture center of Kankan aimed at producing monosex male fry of Oreochromis niloticus in order to increase the yield of this species. During this study, 95 Oreochromis niloticus broodstock including 21 males and 74 females were paired (spawned) in a spawning tank of 135 m 2 surface for 15 days. The respective mean weights of the spawners were 448.6 ±157.7 g for males and 406.7±115.9 g for females. Hormonal treatment was performed on 900 larvae with an average initial weight of 0.028 g from the 10 th post fertilization to the 38 th day in a tank of one (1) m 3 . The larvae were fed with 1 kg of imported "Raanan Premium Fish" powdered feed titrated with 40% protein, mixed in a hormonal solution containing 17-α-methyltestosterone and 90% ethanol with respective doses of 100 mg and 500 ml. At the end of hormonal treatment, 578 fry with a final average weight of 4.5 g were conducted in a pre-pregnancy tank with a surface area of 50 m 2 for 30 days and yielded at the end of pre-pregnancy 501 fry with a final average weight of 13 g, a daily growth rate of 0.22 g, a specific growth rate of 1.7%, a survival rate of 64% and a mortality rate of 36%. After sex identification (sexing), the rates of hormonal treatment were 83.33% and 16.66% for males and females, respectively. In conclusion, the popularization of the results of this study could be considered as an alternative for a production of monosex male population in Oreochromis niloticus that will feed the networks of local producers to improve the production of the species throughout the country. Keywords: Oreochromis niloticus, hormone, sex, larvae and tank. INTRODUCTION Fisheries and aquaculture are major sources of food for hundreds of millions of people around the world. Today nearly half of the fish consumed in the world comes from fish farming (44.1%) 1 . In almost all African countries, fish farming is dominated by Oreochromis niloticus but its farming is limited to subsistence farming and its production is estimated to contribute only around 1.5% of global production 2 . In the Republic of Guinea, more than 80% of fish farmers raise Oreochromis niloticus because of its availability and resilience to fish farming activities, yet the lack of reliable breeding techniques leads to low income levels for fish farmers 3 . However, in the prefecture of Kankan, more precisely in the urban commune, fish farmers use two methods to control their reproduction: the first, manual sexing based on the sexual dimorphism of the urogenital papilla, is a technique that requires labor and time. In addition, this last method results in errors of 2.7 to 10% and an elimination of 50% of the population after three months of rearing. The second, which is rearing in association with predators such as Hemichromis fasciatus and Heterobranchus isopterus, whose role is to consume part of the fry produced during rearing, is a system that requires rearing by age class and therefore a significant number of infrastructures 4 . On the other hand, although the technique of hormonal inversion is applied on a large scale in the world, it is not yet practiced in the fish farms of Kankan due to the lack of technical skills of the actors involved in this activity. However, this technique consists of producing male fry from synthetic hormones while limiting excessive reproduction in the grow-out structures, which leads to excessive recruitment of juveniles, food competition and the blocking of growth of the farmed stock, which cannot reach market size. Additionally, hormonal inversion is considered a reliable and economically profitable technique, reducing the length of the production cycle and accelerating the growth of the fish. This is why the acquisition of precise knowledge of this practice by fish farmers constitutes a reliable tool to allow an optimization of the performances and a decrease of the production costs in order to increase the level of economic profitability of fish farmers.